Help me out....

*StarFire

plz someone tell me d relation between CPE,Demarcation point,local loop,central office n toll no.

if possible then giv d block digram relating them...........

miller811

CSU or CSU/DSU (Channel Service Unit/Data Service Unit)
A device to terminate a digital channel on a customer's premise. It performs certain line coding, line-conditioning and equalization functions, and responds to loop-back commands sent from the central office. A CSU sits between the digital line coming in from the central office and devices such as channel banks or data communications devices and is found in every digital link and allows the transfer of data at a range greater than 56 Kbps.
Demarcation point between the wiring that comes in from the local telephone company and the wiring you install to hook up your equipment or system to the CPE.

CPE
Customer Provided Equipment

Local Loop
The local loop is the telephone line that runs from the local Telephone Company to the end user's premise. The local loop can be made up of fiber, copper or wireless media. Same as local exchange loop facility whose formal definition is "known as a basic level network access channel, local exchange loop facility means a transmission path capable of delivering analog voice grade signals or digital signals at less than 1.544 Mbps between the network interface at a customer's premises and the main distribution frame or any other point of interconnection to the LEC network."

DEMARC
The physical and electrical boundary between an end user's telecommunication equipment and the telecommunications network. The demarcation point establishes point of ownership and accountability.